The subject matter disclosed herein relates generally to power converters, and more particularly to a system and a method for controlling a plurality of series connected switch modules in a power converter.
Converters, such as direct current (DC)/DC converter or DC/alternating current (AC) inverter or AC/DC converter, employ IGBT modules as basic electronic switches. For high current applications, a typical IGBT module includes two or more IGBTs which can be connected in parallel to provide a larger current. For high voltage applications, a plurality of IGBT modules can be connected in series to provide a larger voltage.
Due to the series connection of the plurality of IGBT modules, a total number of IGBTs is increased, which may reduce reliability of the converter. For example, if there are three IGBT modules connected in series, then when one of the IGBT modules fails, the whole string may not be functional or the other series connected IGBTs may also fail subsequently. The IGBT may have failure due to overvoltage, etc.
In order to ensure the reliability of the converter, a redundancy of the series connected IGBT modules is desired.